8” v 10” radius on Jack plane blade

[Tony Wilkins]

As I mentioned in another thread, I finally have a grinder. First business, putting a radius camber on a blade to use a Jack into a fore plane for heavy work across the grain. Specifically, I’m doing this to a PMV11 iron for a Veritas 5 1/4 (the plain Jane, not custom plane).

The two options I’m looking at are an 8” radius or a 10” radius. Thoughts on one over the other?

[Tom M King]

There's not much difference in use. With the 10" radius you will probably take a little wider cut, not as deep. I think I tried both years ago, and just left it whichever was the last one I tried, but it's been so long ago that I don't remember which that is.

[Rafael Herrera]

Hi Tony,

Try 10" first and see if you get your work done with that. If you don't and want to take thicker shavings increase the camber to 8".

I wonder why you want to use such a nice plane in such a coarse setting. That plane probably has a relatively narrow mouth, you may have issues clearing really thick shavings through it.

[Tony Wilkins]

Hi Tony,

Try 10" first and see if you get your work done with that. If you don't and want to take thicker shavings increase the camber to 8".

I wonder why you want to use such a nice plane in such a coarse setting. That plane probably has a relatively narrow mouth, you may have issues clearing really thick shavings through it.

I don’t have a cheaper plane available for the task. Heck, right now I’m using an LN bronze #4 for the task because I had one of their pre-radiused roughing blades laying around.

[steven c newman]

A Jack plane is NOT meant to be a smooth plane...it is more for the first strokes on rough wood...
472538
Sargent No. 3416...with an 8" radius iron....Can be used like this to rapidly get a board to thickness. You can also go at the diagonals to the grain....

Gossamer Shavings are NOT the job of a jack plane.

Get either a Stanley No. 5...or a Sargent No. 414....or a Millers Falls No. 14.....plenty of them out there, and fairly cheap...

[Jack Dover]

A Jack plane is NOT meant to be a smooth plane...it is more for the first strokes on rough wood...

A jack plane should be capable of smoothing by, like, a definition, since "jack" comes from "Jack of all trades". How is it set up to be able to perform all these tasks is another question.

I have a double iron jack that can smooth pretty well. Not as good as a dedicated smoother with a tight mouth which handles even most difficult grain, but it does a very good job in moderate grain. At any time I can back the chip breaker up, set the iron rank and it will produce shavings thick as a belt. It also joins pretty long boards, once I joined a coffee table top with it, because a joiner was checked into a rehab at that time. In order to enable all this I had to experiment with the camber, initially it had too much radius, so it was taking very narrow shavings when set fine. More pressure in the center when sharpening ground most of the camber off, it's now more or less elliptical with unknown radii. Sometimes I think that if this particular plane would have an adjustable mouth and a spare iron assembly - it could really replace most (or maybe all) of my other bench planes. There would less fun in it though.

You probably meant a "fore" plane. A fore plane is similar in size, but set up for heavy removal. It has a pronounced camber and a wide mouth, and my theory is they were worn down jack planes pretty much like scrub planes were worn down smoothers. Fore planes were superseded (or assumed to be superseded) by scrub planes. Not sure why, a fore plane is way more convenient to hog off wood with, maybe because of the way we hold it, with arms wide apart. I originally learned to use a scrub plane, and have been pretty happy with it until I repurposed one of the planes. The trusty scrubber used to collect dust after that, until it was retired into a display box for all the service he had performed.

[steven c newman]

Like C. Schwarz is wont to say.....as in Fore-most.

I have several Jack planes, including both the Juniors and the Jumbos....A few have no camber, some a lot...one IS set up as a scrub-jack.

Hey, somedays, I even use the WR #62.....

Sometimes..a small Stanley No. 101 gets the call..or a #9-1/2..
472542
Other jobs, I might need that Stanley No. 8c.....I size the plane to the size of the job...

And...lets not get started on whether to groove a sole, or not...
472543
#3c,#4c,#5-1/2c, #6c, #7c, and the #8c....I don't have a #5c, though. Or a #5-1/4c.....
Any different from the smooth sole mob? Not that I have seen....

[Derek Cohen]

As I mentioned in another thread, I finally have a grinder. First business, putting a radius camber on a blade to use a Jack into a fore plane for heavy work across the grain. Specifically, I’m doing this to a PMV11 iron for a Veritas 5 1/4 (the plain Jane, not custom plane).

The two options I’m looking at are an 8” radius or a 10” radius. Thoughts on one over the other?

Tony, many years ago an 8” radius on my jack would have been similar to what most advised. Currently, my jack has a 12” radius. This is because most of my boards are jointed and thicknessed by machines, but occasionally I still need to work them with a hand plane. Since there is less thickness to remove - less need for the jack to substitute for a scrub plane - I would rather take a wider and shallower cut. Set the radius according to your needs.

Regards from Perth

Derek

[Scott Winners]

Yes to all. I was going to suggest waiting for Tom M King to stop by, but his deeply experienced response is the same as I have found with a little tiny bit of experience. 8-10" radius is pretty much the same.

I would not do that to a PMV-11 iron. You could go to the homestore and get a new "Stanley #4" for about 20 bucks. You can't hurt it. I was not able to tune mine into a smoother, but I was able to make a pretty fine scrub out of it.

A scrub plane will need a wider mouth opening (measured fore and aft) than a smoother will. Just grab a cheap plane at the home store and get busy with your grinder and file.

FWIW my homestore #4 now has a 3" radius on it and a wide mouth that works great on building sized timbers, like a rough sawn 4x10 that is 12 feet long. From there I go to a my #6 with I think a 9" radius on the iron, and then I am ready for regular plane irons shaped straight across with a bit of round over on the corners.

[Jim Koepke]

Specifically, I’m doing this to a PMV11 iron for a Veritas 5 1/4 (the plain Jane, not custom plane).

My first scrub plane was a Stanley/Bailey #5-1/4.

472589

The blade in the center is from my #5-1/4. The others are from a #5 & #40.

It should be possible to check the blade for the radius tomorrow, haven't been in the shop for a couple of days.

jtk

[Justin Allen]

I recently did this to the same plane for flattening smaller stock, and went with a 10" radius. That allows for .035" (just over 1/32") depth of cut when the corners are even with the plane sole, which was plenty for my needs. Even in the SYP I was planing, it was not easy.

I did find on that plane that when taking heavier cuts like this to make sure the lever cap was fairly tight...the blade would want to recess a bit.

[Jim Koepke]

Sorry it took me an extra day to remember to look into this. The radius on my 1-3/4" blade in a #5-1/4 lines up to my circle template with a 2-11/16" radius.

This size works well for me with an approximately 1" wide shaving hogging away.

jtk

[Andrew Seemann]

I never realized radiusing a jack plane was such a precision endeavor. I just eyeballed it freehand on the grinder until it looked about right and left it at that

[Tony Wilkins]

I never realized radiusing a jack plane was such a precision endeavor. I just eyeballed it freehand on the grinder until it looked about right and left it at that
I’m sure it will end up that way, just wanted a line to shoot toward.

[Scott Winners]

I never realized radiusing a jack plane was such a precision endeavor. I just eyeballed it freehand on the grinder until it looked about right and left it at that


This is a fine approach for a scrub plane. I was a bit concerned about symmetry R/L and build a very simple jig for my belt sander. A bit of double sided tape, a bolt in the correct pair of holes, symmetrical blade crown.

472789

[Jim Koepke]

I never realized radiusing a jack plane was such a precision endeavor. I just eyeballed it freehand on the grinder until it looked about right and left it at that

Andrew, my blade wasn't even radiused at first. It was just waved back and forth on the stones when sharpening. The corners were kind of cut back about a half inch. Over the next few sharpening sessions the shape became a smoother round done by eye. Today it was measured by comparing it to some shop made circle templates:

472797

These come in handy often.

jtk

[steven c newman]

Cheap jack plane ($6~ maybe).
.472828
A "no-frills" plane...
472829
So cheap...that it only used a single bolt to hold the frog in place...although there is a tight fitting rib involved, too...

As for the cambered, bevel down iron?
472830

Mean looking critter, ain't it? It treats all things the same....be it knots, dried glue..rough sawn lumber....sharpened up once every 2 years, or so...

A dedicated Scrub Jack Plane. Nice to have when you need to .....Great Neck, Corsair C-5......

[Assaf Oppenheimer]

I know that sharpening an 8" radius with a guide is harder than a 10"

[Tom M King]

I have an old Record guide that has a small roller ball. You can even use it on a Scrub plane iron. I don't know much about it, other than it's red, and made by Record.

I would never use it for a narrow chisel like in the picture. It was just to show the setting jigs can be used with anything. It's the red one. The roller doesn't look like a ball in this picture, but it is part of one with flat ends. I have no idea when they made them.

[Assaf Oppenheimer]

I like the angle jig!

[Tom M King]

They work with any jig, and cutter thickness has no effect on the angle. Exactly, and easily repeatable every time. Nothing to fumble with.

[Assaf Oppenheimer]

This is a fine approach for a scrub plane. I was a bit concerned about symmetry R/L and build a very simple jig for my belt sander. A bit of double sided tape, a bolt in the correct pair of holes, symmetrical blade crown.

472789

Hi Scott,

I'm not sure I understand how it works - could you maybe elaborate?